


The One Where Koschei Goes All BDSM on Theta's Arse

by codswallop



Series: That Series Where Theta and Koschei Use Kinky Sex to Screw with Each Other's Heads [2]
Category: Doctor Who
Genre: Bondage, M/M, Non Consensual, Sex Toys
Language: English
Status: Completed
Published: 2009-10-09
Updated: 2009-10-09
Packaged: 2017-10-12 13:16:59
Rating: Explicit
Warnings: Rape/Non-Con
Chapters: 1
Words: 3,650
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/125217
Author URL: https://archiveofourown.org/users/codswallop/pseuds/codswallop
Summary: <blockquote class="userstuff">
              <p>In which Koschei gets a bit carried away. As he does. Follows "The One Where Koschei Lets Theta Top for a Change."</p>
            </blockquote>





	The One Where Koschei Goes All BDSM on Theta's Arse

**Author's Note:**

> Thanks to aralias for the beta.

Theta wasn't the only one who could neglect his studies in favor of extracurricular research on subjects that would have made his professors turn pale. Koschei had decided there might be more to this sex thing after all, and spent the next few days doing some highly interesting reading of his own. After that he disappeared into the Academy's metallurgy lab for a feverish twenty-four hours, and emerged with a cylindrical object which he proudly thumped down on Theta's study desk in their dorm room that night, right in the middle of his _History of the Future_ text.

Theta blinked a few times. "Shiny," he said, finally. "What is it?"

"Sonic paperweight. Latest model. Sings the secret Prydonian anthem in twenty-seven different languages. No, it's a dildo, you ninny; I thought you were supposed to be the expert on all this stuff."

"I've never seen one like that," Theta said, poking it suspiciously with the tip of his stylus. "It's _metal_ ," he observed.

"Stainless steel alloy. Looks cool, don't you think? Come on, you know you want to try it out."

Theta gave him a pale, round-eyed look. "I don't think so," he said apologetically. "I mean...it does look very...cool, yes. But I've gotten awfully behind lately, you know; I was going to try actually _studying_ tonight, a bit."

"Oh, classes." Koschei waved a dismissive hand. "Do it later. Come and play with me--I want you."

"I can't _always_ say I'll do it later." Theta sounded edgy now. "Because later there'll be something else shiny that comes along, and before you know it I'm failing three classes, and--oh." He stopped, because Koschei had shoved Theta's chair backwards and sat down straddling his lap, and was now nibbling very softly and persuasively at the side of his neck. "Okay," Theta said, helplessly. "Since you put it like that. I can study later. I suppose. I-- _oh._ " He broke off again as Koschei bit down on his collarbone. Theta drew a shuddering breath, cupped Koschei's skull in his hands and kissed him hungrily, and the desk chair went over, spilling them both onto the floor in a tangle of limbs. They picked themselves up off the floor, still kissing, shedding clothes, and stumbled blindly toward the bed.

 _Kind of scary how it takes over,_ Theta was thinking dimly, though the forefront of his mind was mainly caught up in noticing how much he liked it when Koschei made that sound, _that_ one, there, when he flicked a fingernail across one of his nipples.

 _It's not scary,_ Koschei scoffed, pushing Theta down on his back. _Just another kind of science experiment really. It's just me, it's just you. What's scary about that?_ He reached up to the drawer where they kept the lubricant solution Theta had concocted, and Theta let his legs fall open in anticipation. Koschei watched him; he loved seeing Theta's face when he did this, his eyes widening slightly at the first shock of penetration, his open trusting expression going vague and cloudy as Koschei worked a second finger into him.

"I want to tie you up," Koschei told him, sending him a mental image of exactly what he had in mind: Theta splayed and taut and helpless and _beautiful_. Theta gulped, and Koschei watched the flush of embarrassment and excitement wash through his mind and then manifest itself on his skin in a blush which spread right down his chest.

"Okay," said Theta. Sometimes he liked to argue with everything Koschei said, on purpose just to annoy him, and Koschei had been afraid it would be one of those times, but something had shifted and he could tell that right now was one of the other times, when Theta would go along with absolutely anything he asked.

Which wasn't exactly what Koschei wanted, either. He wasn't sure _what_ he wanted, suddenly, except that it was welling up dark and vicious from the back of his mind and maybe it _was_ a little scary, after all. He pushed the thought away, bending to kiss Theta's exposed throat and fluttering the fingers that were still inside him. Theta gasped and arched his back, thinking _yes_ at him, thinking _anything you want Kos anything I'm yours_ and that was good, that was incredible, actually, what more could Koschei want than that?

He still wasn't sure ten minutes later, when he had Theta's wrists and ankles lashed firmly to the bedframe with cloth strips torn from his robe. ("Why _mine_?" Theta had complained, showing a brief crack in his _anything you want_ demeanor. "Because yours are always a wreck," Koschei pointed out.) It was good, it was right, it matched the picture in his head, but he was obscurely irritated. Why did Theta have to be so compliant? Was he _humoring_ him, or...? He was half tempted to call the whole thing quits and piss off back to the labs, burn out his bad mood in a few messy chemical explosions. Leaving Theta naked and tied to the bed, of course. He'd be _furious_ and that was always good fun.

"Koschei," Theta cut in. "If you don't touch me, _soon_ , I'm going to yell _FIRE_ at the top of my lungs and let you come up with an explanation to whoever breaks down the door. Does _that_ sound like good fun?"

"Will you now?" Koschei said, reaching out and tracing the letter _kos_ on the shivering skin of his stomach. "I'll be out of the room and down the hall before you get the word out, though." He traced _chei_ with a flourish, then leant down and retraced the letters with his tongue, as an afterthought.

"You're not wearing any more clothes than I am," Theta said, his voice rather uneven, "so that'll be really interesting, won't it?"

"It will," Koschei agreed, and painted a few more letters with his tonguetip to spell out some really rude suggestions, or as rude as you could get in Gallifreyan, which wasn't terribly rude. Theta squirmed beneath him, and he planted a hand in the center of his chest to hold him down. "I'll be yelling for help, though. The whole thing was your idea, after all, you dangerous mind-controlling lunatic, you."

Theta gave a short panting laugh. "You think anyone'd actually believe that?"

"Hmmm. I can be pretty persuasive, you know," Koschei murmured, kissing the soft skin of Theta's lower belly, and then gave him a good hard nip. Theta yelped. "Anyway, it'd be interesting to find out," Koschei went on, ignoring him. "But what I really want to do, right now, is try out our new toy here." He got up and fetched it from the desk, turning it over in his hand, admiring the flawless sheen of its metallic surface. "I went to a lot of trouble over it; it'd be a shame to get it confiscated before we have a chance to break it in."

He looked over swiftly at Theta, then, because the warm glow of Theta's thoughts had just given off a staticky crackle. "Really?" Koschei asked, intrigued, as he applied a coating of lube to the object in his hand. "Makes you nervous, does it?"

"It looks sort of, well, cold," Theta admitted. "I don't suppose you could _oh Rassilon's sweet balls_ , Koschei, you miserable cruel beast. My heart. Just stopped. The left one. I swear."

Koschei paused and pressed an ear to Theta's chest. "Liar," he said dismissively, and went back to what he'd been doing. It was _fascinating_. He was fully engaged in Theta's mind, witnessing his reactions from the inside and out, and Theta was reacting very strongly indeed to the slick metal object sliding into his body. It wasn't painful for him, exactly; there was at least as much pleasure in the mix as discomfort, but it was a complicated, unwilling sort of pleasure, and Koschei could feel him trying to resist, forcing himself to relax, and then tensing up again.

"You don't like this much," Koschei observed after a bit. "Why not? I wonder."

Theta made a face, his gaze fixed on the ceiling. "I don't know. It's cold, it's mechanical, it's a...a _thing_ ," he said, and shuddered all down his body. "It's you doing it but it's _not_ you. And you like that I don't like it," he added, turning his eyes directly to Koschei's face for the first time. "Why's _that_?"

Koschei looked away. He couldn't deny it; he couldn't remember ever being quite this aroused before. His breath was coming in short, hitching gasps, as things that had been shadowy and dormant inside him till now began to click and whir and stir to life. He was rock-hard, he noticed suddenly, and part of him wanted badly to yank the dildo out of Theta's body and bury himself to the root there instead. And he would. In a minute. Just...not quite yet. Instead he drew it out partway and then pushed it in deeper, and Theta made a choked-off trembling sound that made him shut his eyes.

The crackling in Theta's mind was getting louder and sharper now, turning to lighting-flashes of real alarm that cut across the ink-stain of dark excitement spilling through Koschei's consciousness. "Koschei," Theta said, and then switched over to saying it in his head, because his voice had gone all warbly. _Kos. Look at me. What would you do if I said Stop?_

"I don't know," Koschei told him, grinning. "Why don't you try it and see?"

And Theta didn't say anything, because he knew what would happen. Eyes locked on each other's, they both knew.

"You don't want me to stop," Koschei taunted. "You're as turned on by it as I am, I can tell." He gave the dildo a sharp twist, and Theta bit his lip, hissing.

"That doesn't mean--" he began, through gritted teeth, but Koschei interrupted him.

"I'll _make_ you like it," he said. "Isn't that what you said to me?"

"That was _different_ ," Theta bit out, flexing his wrists subtly to see if there was any give in the bindings (there wasn't). "I would have stopped. If you'd said. You know I would."

Koschei looked down, at the mesmerizing sight of his own hand gripping the cold steel, forcing it slowly in and out of Theta's body. At the hard arc of Theta's cock, and the slight unwilling buck of his hips in rhythm, despite the storm in his mind of anger and fear and...disappointment, was it? Koschei swallowed.

"Beg me," he said softly. "Beg me, and I'll stop."

He sat back on his heels and watched the struggle play out in Theta's mind. Theta's mind, which he loved so: the intricate crystalline landscape of it, its contours and convolutions almost as familiar to Koschei as his own. The problem sat like a three-dimensional snarl right in the center, and Theta circled around trying to see all sides of it, gauging its complexities and looking for the weak spot where it might unravel, not even bothering to try and guard his thoughts from Koschei's view. _Give in_ , he was considering. _Give Koschei what he wants, for now at least,_ because Theta did like to give Koschei what he wanted, quite often, but he was afraid that in this case it was a dangerous thing for Koschei to be given. And he didn't want to, he just purely didn't want to. Didn't want to lose, didn't want this experience to go on any longer, and giving in was no real guarantee that Koschei would keep his end of the bargain and release him.

"You could try yelling Fire now," Koschei suggested, gleefully malevolent. "Be a real treat for whoever breaks down the door. And you _might_ be able to think up a convincing story to explain it. But it'd probably end in expulsion for at least one of us. If you care about that."

Theta did care about that, it seemed. He continued to weigh his options. He could do nothing: remain inert, withdraw. Just refuse to react and hope Koschei would lose interest. He hadn't had enough experience in training his body to respond to his mind's commands, though; his body was the battleground here, and its reactions would betray him no matter what. Just the thought of it caused him to flex against his bindings again in fruitless struggle.

"It pulls the knots even tighter when you do that," Koschei observed. "So what _are_ you going to do? I'm really curious now."

"This isn't a fucking _chess game,_ Koschei," Theta spat. "You do realize you're crossing a line here. What do you think's going to happen when this is all over?"

Which volleyed the problem over into Koschei's court. It was an issue, true. But the line had already been crossed, hadn't it? He'd be able to talk himself back into Theta's good graces later on, or he wouldn't and he'd have to deal with that. The damage was already done, either way, as he saw it; he might as well come out the winner as the loser, for all it mattered, and he infinitely preferred to win.

"It's not too late, though, Kos," Theta said, and his animal brain was still sending out shocks of _fear trapped escape escape_ but he'd gained enough control to be able to use his calm commanding voice, the one Koschei loved and hated and usually couldn't help responding to. "Untie me, and we'll talk about it, okay? It's my fault too; I shouldn't have let you, I should have known. But if you end it now, it's not losing, it's just...stopping something we shouldn't have started. All right?"

Koschei looked at the blank white dormitory wall, breathing hard, letting Theta's cool reasonable thoughts sink into his own hot inner turmoil, coaxing the cacophony of jagged edges and spikes back down into a soothing geometry of straight lines and right angles. He hesitated.

 _Please, Kos,_ Theta urged, pitching slantwise into a more desperate tone, and that was his mistake, because that note of plea went piercing into Koschei's secret core, unleashing all the dangerous things he kept locked away in the farthest closet down the narrowest hall of his mind. He felt something snap and rush loose with wild excitement.

"All right," Koschei said, and laughed in a kind of relief, reaching out to cup Theta's chin in his hand and then leaning over and kissing him. Theta kissed back, after a minute, confused but encouraging; he could tell something had just kicked on with tremendous force in Koschei's mind, but Koschei was keeping it shielded and he couldn't see what it meant. "All right, you're right, I'll stop," Koschei assured him, speaking into the warmth of Theta's neck, feeling him shiver. "Right after I make you come." And he reached down, between Theta's legs, and twisted the hidden mechanism that made the dildo vibrate deep inside him.

Theta's whole body jerked and went rigid, and his calm reasoning thoughts scattered into shreds of blind panic. "Koschei, _no_!" he cried out. "I don't want to, you can't, it's-- _please stop_ , I'm begging, if that's what you want, _please_ \--"

"Shhh," Koschei told him, his turn to command now. He felt amazingly calm. He was the center of a maelstrom; any doubts about what he was doing had fled. "It's too late for that now, Theta, we're going to finish this the way I want. Come on, it's all right, just do this for me and then it'll be over. You're almost there, I can feel it."

It was true, there was a part of Theta that was responding to this just as much as Koschei was, although he hated it and was fiercely ashamed to discover it--Koschei could sense that, too. And Koschei's own excitement had swelled to a loud crescendo that dizzied them both; with their minds conjoined, Theta felt it just as he did, and his body couldn't help responding. He fought against it, but the struggle only added to Koschei's arousal and therefore his own.

"I _don't want this_ , Koschei," Theta told him in a harsh, intense whisper, trying to will his body to go limp and slack. "This changes everything, you know that, don't you? You're willing to do that to me, to yourself--to _us_?"

Koschei paused. He slipped the dildo out of Theta's arse--Theta shuddered with relief--then brought it back up to tease at his perineum, making him writhe and whimper. He thought about what Theta had just said; he thought about everything changing. He thought about Theta's sweetness and his wide-open trusting blue eyes and his smug self-righteous moral superiority and where the _fuck_ did he get off thinking he had the right to be _disappointed_ in Koschei, anyway?

"Yeah, I am," he said, looking straight into Theta's face, watching the muscles twitch as he tried not to fall apart visibly--which was rather funny, since of course Koschei could see all the way through to the place where he was curled up in his head, crumpled and destroyed. "Besides, you'll forgive me. You always do." And he pushed the vibrator back in, deep, angling it to a spot that made Theta throw back his head and give a strangled scream, arching in helpless pleasure. Koschei bent his own head to take him into his mouth at the same time, just in time to catch the jet of semen.

Nothing had ever been sweeter. Nothing. Koschei wanted to drink it down and savor the taste of Theta's defeat, but he didn't; he had another idea, suddenly, and climbed up Theta's body to kiss him, pushing the come into his mouth with his tongue. "Swallow," he commanded, mostly to hear himself say it, because Theta was already complying, with only a short sob on the outside, but on the inside he was lost, lost, reeling and broken. "Good, that's good. Good boy," Koschei breathed, and then " _Oh._ Theta. Oh," and came strongly, grinding against Theta's belly, shaken and blinded by the brief agony of too much pleasure.

He'd be magnanimous, Koschei decided, in the panting, sticky silence that followed. He wouldn't lord it over Theta. He'd get to be the strong one, put him back together, comfort him. He was looking forward to it, actually. He let himself collapse on top of Theta's limp body for a few moments, covering it with his own, adoring what he'd gained dominion over. Then he sighed, and got up and fetched a knife from the worktable to cut the cloth strips holding Theta down. They'd left terrible welts in a few places, he'd have to get some ointment from the infirmary. Theta would probably be pretty knocked-out for the rest of today at least, he might even--

Koschei never saw it coming, the fist in his face, the knife at his throat. He lay stunned and blinking on the floor, vaguely impressed, so far as he was able to think.

"I will _never_ ," Theta told him, from two inches' distance, "give you the chance to do that again. And I _won't_ forgive you. _Ever._ " He snatched his torn robes from the floor and slammed out of the room.

*

He did, though, of course. It took quite a while. There were Scenes. Theta moved out of their shared room, refused to meet his eyes when they encountered each other in public, shut him out with steely determination when Koschei tried to nudge into his mind. Koschei pretended not to care for all of three weeks, then lost it completely.

"I'm going mad," he announced out loud to Theta in the middle of the library one day, unshaven and disheveled, not caring that they were surrounded by at least a dozen shocked and curious fellow students. "You have to at least talk to me. Or I'll start screaming and won't be able to stop. I'll tell everyone why, too. Do you want that?"

"Charming, Koschei," Theta muttered in disgust. "Really classy of you, very mature. All right, we'll talk. Not here, though. Pull yourself together, can't you?"

"I'm sorry, Theta," Koschei said. "I'm so sorry. I don't know what came over me, it was _horrible_ , you have to help me, you're the only one who--"

"Shut. Up," Theta hissed. "Outside. _Now._ "

It wasn't entirely an act. Not entirely. Theta would have seen right through it if it had been. No, his remorse was real enough, his need for Theta's companionship, his own fear at having glimpsed the black depths of his craving for control. A small, hidden part of him was curious to see if he could win Theta back not knowing the full truth, though. If he could let Theta see just enough to pity him, holding back the part of himself that still laughed in the dark and gloated over what he'd done. What he could do again, perhaps. Theta, he suspected, would never be able to resist the opportunity to call him back from that darkness; he would always be just arrogant enough to believe he had the ability to bring him back in line. It was comforting, in a way.

"But no more tying up," Theta conditioned, still looking troubled, the day he finally agreed to move back into Koschei's dorm room. "No more unusual shiny objects, and if we have sex you have to let me all the way inside your mind the whole time, or I'll tie _you_ up and...and..."

"Recite really bad Earth poetry to me till I beg to regenerate with no ears?" Koschei suggested.

"You're not taking this seriously," Theta said, getting up to leave.

"I am, I am," Koschei said, stopping him. "Anything you say, Theta, I swear it. You win, all right? You win."

 _For now,_ he couldn't help adding to himself, and if Theta heard it, he pretended not to.


End file.
